Biomedical subjects

H Seki

Publications and source records attributed to H Seki.

At least 109 records · Page 6Linked to original sources

PubMed1997

The regulation of progesterone and hCG production from placental cells by interleukin-1beta.

We have investigated the roles of interleukin-1beta as a regulator of progesterone and chorionic gonadotrophin production from human placental cells. In primary placental cells IL-1beta increased hCG synthesis through a cyclic AMP-independent pathway, and was without effect on progesterone or cyclic AMP production. Since dibutyryl cyclic AMP increased progesterone production, this suggests that there is no coupling between the IL-1beta receptor and the adenylate cyclase enzyme in these cells. Immortalised trophoblast cells responded to IL-1beta by increasing progesterone production through a cyclic AMP-dependent mechanism, but hCG production by these cells was unaffected by IL-1beta or dibutyryl cyclic AMP. Further studies are needed to identify the role of IL-1beta as a possible regulator of progesterone production in primary placental cells. While hCG production in first-trimester trophoblast was increased by dibutyryl cyclic AMP and IL-1beta, both these effects may involve other factors such as IL-6, and their second messenger systems.

Cells, Cultured↗

PubMed1997

A New Method for the Removal of Toxic Metal Ions from Acid-Sensitive Biomaterial

A new method (competitive adsorption method) for the removal of toxic heavy metals from acid-sensitive biomaterials was proposed and it was applied to the removal of cadmium from the mid-gut gland (MG) of scallop, Patinopecten yessoensis. Insolubilized humic acid, which has been developed in our laboratory, was used as a competitive adsorbent. A metal-complexation model was used to determine the adsorption characteristics of cadmium onto MG. Furthermore, the model was applied to the competitive adsorption system. The results showed that the competitive adsorption method enabled the simultaneous removal of toxic cadmium from both liquid and MG phase under mild acidic condition (pH 5).

Journal Article↗

PubMed1997

Involvement of reactive oxygen intermediates in spontaneous and CD95 (Fas/APO-1)-mediated apoptosis of neutrophils.

Apoptosis is well known to be mediated by oxidative stress. To evaluate the functional role of reactive oxygen intermediates (ROI) produced by neutrophils, we compared the rates of apoptosis in neutrophils isolated from normal donors and from patients with chronic granulomatous disease (CGD), a hereditary defect in ROI production. Spontaneous cell death in CGD neutrophils in vitro was significantly inhibited relative to normal neutrophils. The acceleration of apoptosis induced by anti-Fas monoclonal antibody (MoAb) in CGD neutrophils was much slower than that seen in normal neutrophils. These findings suggest that the apoptosis of neutrophils may be mediated by endogenous oxidative products. This suggestion was confirmed by observation that apoptosis of normal neutrophils was markedly inhibited by reduction of intracellular levels of hydrogen peroxide (H2O2). The inhibition of apoptosis in normal neutrophils by adding catalase occurred regardless of the presence of anti-Fas MoAb. H2O2 increased both spontaneous apoptosis and Fas-mediated apoptosis of the CGD neutrophils in proportion to that seen in normal neutrophils. Although several factors that mediate the apoptosis of neutrophils remain to be determined, these results suggest that ROI are major mediators of the apoptosis in neutrophils and may be involved in Fas-mediated signal transduction pathway.

Apoptosis↗

PubMed1997

Myometrial invasion of endometrial carcinoma: assessment with dynamic MR and contrast-enhanced T1-weighted images.

AIM: To evaluate the usefulness of dynamic magnetic resonance (MR) imaging in assessing the depth of myometrial invasion, compared with conventional T2-weighted and contrast-enhanced T1-weighted imaging. PATIENTS AND METHODS: Forty patients with endometrial carcinoma were examined with T2-weighted images, dynamic studies and contrast-enhanced T1-weighted images, preoperatively. We evaluated enhancement patterns of myometrium and tumour, and compared MR findings with histological results concerning the depth of myometrial invasion. RESULTS: In assessing the depth of myometrial invasion, the accuracy of T2-weighted images, dynamic studies and contrast-enhanced T1-weighted images was 58%, 85% and 68%, respectively. The tumour-myometrial contrast of dynamic studies was higher than that of other images. In addition, subendometrial enhancement (SEE) was frequently observed in dynamic studies in post-menopausal women, which was an important landmark in detecting myometrial invasion. CONCLUSION: We consider that dynamic MR imaging has greater advantage in assessing myometrial invasion than T2-weighted or contrast-enhanced T1-weighted imaging.

Adult↗

PubMed1997

Pheochromocytoma in pregnancy manifesting hypertensive crisis induced by metoclopramide.

Pheochromocytoma is a rare disease that may occur during pregnancy. Antenatal diagnosis is essential to improve fetal and maternal mortality and morbidity, but is difficult. A hypertensive crisis was induced by metoclopramide, a widely used anti-emetic, in a pregnant normotensive woman. Biochemical measurements of plasma and urine catecholamines and magnetic resonance imaging (MRI) established the diagnosis of pheochromocytoma. She was medically treated with prazocin and electively delivered by cesarean section simultaneously with tumor resection.

Adrenal Gland Neoplasms↗

PubMed1997

A ruptured aneurysm at the distal end of the basilar artery fenestration associated with multiple fenestrations of the vertebrobasilar system: case report.

BACKGROUND: An aneurysm at the fenestrated basilar artery usually arises at the proximal end of the fenestration, with few exceptions. We failed to reveal any case of aneurysm at this site associated with multiple fenestrations of the vertebrobasilar system. CASE REPORT: This 62-year-old male was admitted to our hospital 1 day after a sudden onset of headache. CT scan showed subarachnoid hemorrhage, and angiogram revealed an aneurysm at the distal end of the fenestrated basilar artery in association with two other fenestrations of the vertebrobasilar system. The limb of the basilar artery fenestration was trapped tightly with one clip through the transcondylar approach. Postoperative course was uneventful, and postoperative angiogram showed complete disappearance of the aneurysm. CONCLUSION: An extremely rare case of an aneurysm at the distal end of the fenestrated basilar artery in association with multiple fenestrations of the vertebrobasilar system is reported. The coexistence of vertebral artery fenestration and the fenestration of the vertebrobasilar junction may give a clue to the mechanism of occurrence of basilar artery fenestration.

Aneurysm, Ruptured↗

PubMed1997

Coronary calcification and coronary atherosclerosis: site by site comparative morphologic study of electron beam computed tomography and coronary angiography.

OBJECTIVES: We compared, on a site by site basis, the morphologic features of coronary calcifications determined by electron beam computed tomography (EBCT) and angiographically defined coronary atherosclerosis. BACKGROUND: Quantification of coronary calcification using EBCT is clinically useful for the prediction of coronary stenosis. However, the relation between calcification and angiographic findings has not been evaluated by site. METHODS: We studied 251 consecutive patients who underwent elective coronary angiography for suspected coronary artery disease by EBCT and analyzed findings by site. Coronary calcifications were classified according to their length and width versus the diameter of the coronary artery in which the calcification was observed as: none, spotty, long, wide and diffuse. RESULTS: Coronary calcifications were found in 666 (27%) of 2,470 segments. The positive predictive value (PPV) of coronary calcification for significant stenosis (> or = 75% densitometric narrowing) and for all angiographically detectable atherosclerotic lesions in a segment was 0.36 and 0.80, respectively. The PPV for significant stenosis and all atherosclerotic lesions was 0.04 and 0.17 in none, 0.18 and 0.59 in spotty, 0.32 and 0.87 in long, 0.40 and 0.84 in wide and 0.56 and 0.96 in diffuse calcifications, respectively. The PPV for both significant stenosis and all lesions differed significantly (p = 0.001) among the morphologic groups. Of the 105 eccentric significant stenoses, 54 (53%) were classified as long or diffuse calcifications. Of the 95 significant stenoses with multiple irregularities, 61 (64%) showed diffuse calcification. CONCLUSIONS: Morphologic evaluation of coronary calcifications using EBCT improved the prediction of coronary stenosis on a site by site basis and provided information related to angiographic morphology.

Adolescent↗

PubMed1997

Decreased expression of 20-kD homologous restriction factor (HRF20, CD59) on T lymphocytes in Epstein-Barr virus (EBV)-induced infectious mononucleosis.

HRF20 (CD59) is one of the membrane-associated complement regulatory proteins. The characteristic function of CD59 is to prevent membrane attack complex (MAC) formation on the cell surface and to protect the cell from complement-mediated cell lysis. We examined the expression of CD59 antigen on T cell subpopulations in patients with acute infectious mononucleosis (IM) and analysed the relationship between the amount of CD59 expression and activation-induced cell death of mature T cells with apoptosis. Decreased expression of CD59 on CD8+ T cells, especially on CD45RO+ and HLA-DR+ activated T cells, was marked in acute IM patients. In contrast, activated CD4+ T cells from IM patients expressed as much CD59 antigen as CD4+ T cells from healthy volunteers. After incubation-induced cell death, viable CD8+ T cells showed normal amounts of CD59 antigen on their surface. CD59dim CD8+ T cells were more susceptible to apoptosis than CD59bright CD8+ T cells. These findings suggest that decreased expression of CD59 on CD8+ T cells may discriminate the susceptibility of activated CD8+ T cells to activation-induced cell death in IM.

Acute Disease↗

PubMed1997

The management of cervical incompetence with protruded membranes into the vagina by vaginal irrigation with granulocyte elastase inhibitor: ulinastatin and PVP-iodine solution.

In an attempt to prevent preterm premature rupture of the membranes (PPROM) and to prolong the duration of pregnancy in patients with a dilated cervix and with the membranes protruding into the vagina, the combination therapy of irrigation with a solution containing granulocyte elastase inhibitor (ulinastatin) and PVP-iodine onto the membranes, as well as the use of antibiotics and tocolytic agents, was tested. Ten patients with protruding membranes were treated by this combination therapy and five patients were instructed to have strict bedrest without any medication. In the non-treated group, all patients were delivered within 2 days of admission and all babies had a poor prognosis. In the treated group, the pregnancy was prolonged by between 3 and 108 days (mean values 33.6 days). Only two out of 10 patients had PPROM. In cases with protruding membranes, this combination therapy seemed to be useful in preventing rupture and so prolonging the pregnancy and increasing the survival rate of the infants.

Journal Article↗

PubMed1997

Ovarian pregnancy diagnosed in the third trimester: a case report.

We observed a patient with a primary ovarian pregnancy complicated by severe preeclampsia and a presumed fetal anomaly. Diagnosis was made at cesarean section at 30 weeks of gestation. Etoposide, given intravenously at a dose of 100 mg daily for 5 days, prevented massive bleeding during the procedure that was subsequently performed to separate the placenta.

Adult↗

PubMed1997

Carcinomatous change in the cranial metastasis from a metastasizing mixed tumor of the salivary gland--case report.

A 57-year-old female who had had a mixed tumor of the submandibular gland for 30 years presented with a cranial metastasis in the ipsilateral occipital region. Detailed histological examinations of the primary tumor failed to detect any carcinomatous component. In contrast, the metastasis contained a carcinomatous component. This histological discrepancy was confirmed by assessment of the expression of Ki-67 antigen in these tumor specimens and comparison with five typical benign mixed tumors. Cranial metastasis of a histologically benign mixed tumor is extremely rare, and a carcinomatous change in the metastatic tumor is apparently unique.

Adenoma, Pleomorphic↗

PubMed1997

Stromal invasion by carcinoma of the cervix: assessment with dynamic MR imaging.

OBJECTIVE: The purpose of this study was to evaluate dynamic MR imaging in assessing the depth of stromal invasion by carcinoma of the cervix and to compare dynamic MR imaging with T2-weighted and contrast-enhanced T1-weighted MR imaging. SUBJECTS AND METHODS: Forty-one patients with carcinoma that was clinically considered to be confined to the cervix were examined with T2-weighted, dynamic, and contrast-enhanced T1-weighted MR imaging before surgery. We evaluated enhancement patterns of the cervix and tumor and assessed the degree of stromal invasion with MR imaging. The degree of stromal invasion was divided into two groups: superficial disease (no stromal invasion or invasion of < or = 3 mm) and deep invasion (> 3 mm of stromal invasion). Then we compared these MR findings with histologic results for the depth of stromal invasion. RESULTS: With dynamic MR imaging, cervical carcinoma with deep invasion was seen as a focal enhanced area in the early dynamic phase. The cervical epithelium and stroma enhanced less vividly. In distinguishing deep invasion from superficial disease, we found the accuracy of T2-weighted MR images, dynamic MR images, and contrast-enhanced T1-weighted MR images to be 76%, 98%, and 63%, respectively. In particular, the detectability of 3.1-5.0 mm of stromal invasion with dynamic MR images was significantly higher than that with the other techniques: with T2-weighted MR images, we saw 3.1-5.0 mm of stromal invasion in 23% of patients; with dynamic MR images, in 92%; and with contrast-enhanced T1-weighted MR images, in none. Superficial disease was not revealed with any of the three MR techniques. CONCLUSION: We believe that dynamic MR imaging is superior to T2-weighted MR imaging and contrast-enhanced T1-weighted MR imaging when assessing the depth of invasion of cervical carcinoma.

Adenocarcinoma↗

PubMed1997

[Giant thrombosed fusiform aneurysm at the branch of the middle cerebral artery presenting with intramural hemorrhage: a case report].

We report a rare case of a giant thrombosed fusiform aneurysm at the branch of left middle cerebral artery presenting with intramural hemorrhage of the aneurysm. A twenty-year-old man with familial and past history of migraine presented sudden temporalgia on August 13, 1995. Computed tomography (CT) scan on the day of the first attack revealed a well delineated high density area at the left Sylvian fissure, 2.5cm in diameter. Angiogram showed avascular area corresponding to the lesion, but no visualization of the aneurysm. On October 18, this patient presented sudden temporalgia again. CT scan on the day of the second attack indicated new intramural hemorrhage and surgery was performed on October 31. No evidence of subarachnoid hemorrhage was shown during the operation, and the lesion was proven to be a thrombosed fusiform aneurysm at the branch of the middle cerebral artery. The parent artery was clipped at both proximal and distal sides of the aneurysm, and the aneurysm was totally removed with success. Histological finding further supported the idea that the attacks mentioned were due to intramural hemorrhage of the thrombosed aneurysm. Postoperative course was uneventful and the patient was discharged without any neurological deficit. Intramural hemorrhage of a giant fusiform aneurysm is relatively rare, only reported in several autopsy cases. Furthermore, we failed to discover any comparable cases of giant fusiform aneurysm presenting symptoms directly caused by intramural hemorrhage of the aneurysm.

Adult↗

PubMed1997

Studies on the metabolism and disposition of the new retinoid 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl] benzoic acid. 1st communication: absorption, distribution, metabolism and excretion after topical application and subcutaneous administration in rats.

Administration, Topical↗

PubMed1997

Studies on the metabolism and disposition of the new retinoid 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl]benzoic acid. 3rd communication: placental transfer and excretion into milk in rats.

4-[5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl]benzoic acid (CAS 94497-51-5, Am-80) is a new synthetic retinoid which has been shown to have a potent topical antipsoriatic activity. Placental transfer and excretion into milk after administration of 14C-Am-80 to pregnant or nursing rats were investigated in view of reproductive and developmental toxicity studies. When 14C-Am-80 was administered topically at a dose of 10 mg/kg to normal-skin pregnant rats on the 12th day of pregnancy, plasma radioactivity in the dam and fetus was detected only at low levels. However, at a dose of 1 mg/kg to the stripped-skin pregnant rats, radioactivity levels peaked at 6 h in the maternal plasma (188.7 ng eq./g) and fetus (64.6 ng eq./g) and at a dose of 10 mg/kg, the peak maternal plasma level of radioactivity and the concentration of radioactivity in the fetus up to 24 h after dosing rose about 10-fold in proportion to the increased dose. At both doses, the radioactivity level in the fetus at the peak corresponded to approximately one-third of the maternal plasma level. When 14C-Am-80 was administered subcutaneously at a dose of 1 mg/kg to pregnant rats on the 12th day of pregnancy, radioactivity in the fetus peaked at 4 h after dosing, being about one-fourth of the maternal plasma level at the same time point. Radioactivity in the fetus after subcutaneous administration of 14C-Am-80 at a dose of 1 mg/kg to pregnant rats on the 19th day of pregnancy peaked (156.4 ng eq./g) at 4 h after dosing, corresponding to approximately one-half the maternal plasma level at the same time point, and then decreased gradually. Among the fetal tissues, relatively high radioactivity was found in the liver. Whole-body autoradiography showed that in most tissues in the dam, the distribution pattern of radioactivity was similar to that in the non-pregnant rat. The concentration of radioactivity in the milk after subcutaneous administration of 14C-Am-80 at a dose of 1 mg/kg to lactating rats on the 9th day after delivery peaked at 8 h after dosing, being 94 times greater than that in the plasma. Unchanged Am-80 in the milk was largely recovered after hydrolysis of hexane extracts of the intact milk with lipase, suggesting extensive incorporation of Am-80 into the triglyceride in the milk because of its benzoic acid structure and high lipophilicity. As for radioactive metabolites which have hitherto been identified in rats, only M-6 (taurine conjugate of Am-80) and tetrahydro-tetra-methyl-naphthylamine (TTNA) were detectable in small amounts in the milk.

Administration, Topical↗

PubMed1997

Studies on the metabolism and disposition of the new retinoid 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl] benzoic acid. 4th communication: absorption, metabolism, excretion and plasma protein binding in various animals and man.

4-[(5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl]benzoic acid (CAS 94497-51-5, Am-80) is a new synthetic retinoid which has been shown to have a potent topical antipsoriatic activity. Pharmaco-kinetic profiles of Am-80 were studied in dogs, mice and rabbits after percutaneous or subcutaneous administration of 14C-Am-80. Plasma protein binding of 14C-Am-80 was also studied in rats, dogs and humans. After topical application of 14C-labeled Am-80 by occlusive dressing technique at a dose of 1 mg 14C-Am-80/1,000 mg ointment/kg, the blood and plasma levels of radioactivity were below the detection limit in normal-skin dogs. In normal skin mice and rabbits, the plasma radioactivity peaked at 8 h (40.8 ng eq./ml) and at 12 h (34.0 ng eq./ml) after application, respectively. Percutaneous absorption of 14C-Am-80 was less than 2% of the dose for dogs, 34% for mice and 23% for rabbits. After subcutaneous administration at a dose of 1 mg/kg to mice, dogs and rabbits, plasma levels of radioactivity peaked at 1, 4 and 4 h after dosing with a concentration of 614.0, 902.9 and 757.7 ng eq./ml and then it declined with half-lives of 2.4, 7.2 and 4.1 h, respectively. Urinary and fecal excretion of radioactivity after subcutaneous administration at a dose of 1 mg/kg was 3.5 and 94.7% of the dose in dogs, 27.0 and 73.2% in mice and 43.5 and 45.6% in rabbits. A possible gastrointestinal secretion, which might lead to excretion into feces, was suggested from the results with bile-duct-cannulated dogs. Unchanged Am-80 was present in high amounts in the plasma and bile or feces of all animal species tested except in rat bile, in which Am-80 was predominantly detected in the form of its taurine conjugate (M-6). Hydroxylation of Am-80 to yield 7-hydroxy-Am-80 (M-4) and 6-hydroxy-Am-80 (M-3), which lead to the formation of 6-oxo-Am-80 (M-5), were commonly observed in all animal species. Taurine conjugation reaction of unchanged Am-80 and hydroxy-Am-80 (to form M-6 and both M-1 and M-2, respectively) was distinct in rats and dogs, but, hardly detected in mice and rabbits. The presence of tetrahydro-tetramethyl-naphtylamine (TTNA) was most marked in mice, followed by rabbits and rats, but it was almost absent in dogs. HPLC-RIA analysis of human samples obtained from the phase II and phase III clinical trials of Am-80 ointment suggested that fecal excretion was the major elimination route, and that hydroxylation and taurine conjugation reaction of unchanged and hydroxy-Am-80 also occurred. Unchanged Am-80 was predominant in human plasma as compared with metabolites M-1 to M-6. In vitro binding of 14C-Am-80 to the plasma protein was found to be more than 99% in rats, dogs and humans. In vivo plasma protein binding of 14C-Am-80 and/or its radioactive metabolites was also found to be more than 98% in rats and dogs after subcutaneous administration of 14C-Am-80. In both dogs and humans, in vitro. 14C-Am-80 appeared to be bound predominantly to serum albumin. The binding of 14C-Am-80 to human serum albumin was scarcely affected in the presence of diazepam, digitoxin or warfarin, indicating that there are no specific binding sites for Am-80 on serum albumin.

Administration, Topical↗

PubMed1997

Gastric metaplasia and Helicobacter pylori.

OBJECTIVES: We investigated the relationships between gastric metaplasia occurring during the healing and scarring stages of duodenal ulcers and Helicobacter pylori by examining the course of gastric metaplasia in H. pylori-eradicated and non-eradicated patients. METHODS: One hundred and six H. pylori-positive patients with active duodenal ulcers were assigned to either a non-eradication group or an eradication group. The non-eradication group received lansoprazole for 6 wk, followed by an H2-receptor antagonist. The eradication group also received amoxicillin and metronidazole for 1 wk, in addition to lansoprazole, after initial endoscopic examination. In both groups, biopsy specimens were obtained from the ulcer margin in the active stage and from the center of the scar in the scarring stage. Specimens were examined microscopically as well as by rapid urease test to assess the extent of gastric metaplasia and to detect the presence of H. pylori. RESULTS: The extent of gastric metaplasia increased as the ulcers healed. The extent of gastric metaplasia was of a lesser degree in the non-eradication group than in the eradication group at the time of healing, and this tendency became increasingly apparent in the course of follow-up, resulting in reduced defense mechanisms against acidity to promote the recurrence of ulcers. In the eradication group, among those in whom eradication was successful, gastric metaplasia presented a well-developed appearance with abundant intracellular mucus and remained in this condition for a prolonged period, resulting in adequate defense mechanisms against acidity to prevent the recurrence of ulcers. CONCLUSION: By the eradication of H. pylori, gastric metaplasia becomes well-developed and remains so for a prolonged period. Thus, the eradication of H. pylori appears to play a role in the prevention of ulcer recurrences by developing adequate defenses against acidity.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1997

[Ewing's sarcoma at the occipital bone presenting as acute epidural hematoma: a case report].

Primary cranial Ewing's sarcoma is rare. We describe an exceptionally rare case of primary Ewing's sarcoma of the occipital bone, presenting as spontaneous acute epidural hematoma. A 19-year-old female was admitted to our hospital complaining of sudden onset of severe headache. There were no neurological deficit and no abnormal laboratory findings. Computerized tomographic (CT) scan revealed a lentiform shaped high density lesion at the left occipital epidural space. Magnetic resonance imaging (MRI) showed the lesion as iso to low intensity on T1-weighted image (T1WI) and mixed signal intensity on T2-weighted image (T2WI). There were no pathological findings at the adjacent brain. Cerebral angiography demonstrated mass effect. Right occipital craniotomy was performed. We found the tumor arising from the occipital bone and located at the epidural space. The tumor was resected totally. Histological examination revealed the tumor as Ewing's sarcoma with intratumoral hemorrhage. The postoperative course was uneventful. Radiation therapy (50Gy) was given. Follow-up examination six years after the treatment found no evidence of tumor recurrence or distant metastasis. It should be born in mind that primary Ewing's sarcoma of the skull can cause spontaneous acute epidural.

Acute Disease↗